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Subject: Re: Maximum benefit of permanent brain?

Author: Robert Hyatt

Date: 12:26:15 11/13/00

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On November 13, 2000 at 13:58:49, Uri Blass wrote:

>On November 13, 2000 at 11:55:08, Robert Hyatt wrote:
>
>>On November 12, 2000 at 15:10:43, Uri Blass wrote:
>>
>>>On November 12, 2000 at 13:25:15, Robert Hyatt wrote:
>>>
>>>>On November 12, 2000 at 12:48:14, Uri Blass wrote:
>>>>
>>>>>On November 12, 2000 at 11:05:30, Robert Hyatt wrote:
>>>>>
>>>>>>On November 12, 2000 at 10:54:42, Jeff Lischer wrote:
>>>>>>
>>>>>>>It seems if you correctly predict the opponent's move 100% of the time, this
>>>>>>>would correspond to doubling your available time (you would be thinking on your
>>>>>>>time as well as your opponent's time). If a doubling of speed results in an Elo
>>>>>>>improvement of 60-70 points, is this also the maximum benefit for permanent
>>>>>>>brain? With diminishing improvements at longer time controls, the benefit might
>>>>>>>be even less?
>>>>>>>
>>>>>>>If the above is correct, then what about the case where you correctly ponder
>>>>>>>only 60% of the time. This seems like a pretty typical value. Then is the
>>>>>>>benefit only about 40 Elo points?
>>>>>>>
>>>>>>>Are there any other approaches to permanent brain that might be more effective?
>>>>>>>At first I was wondering about simply searching on your opponent's time like you
>>>>>>>do on your turn -- using selective searching to focus on the best moves. But
>>>>>>>then I thought of another possibility. What about a different kind of searching?
>>>>>>>Maybe search using lots of knowledge during your opponents time trying to
>>>>>>>develop a plan? Or maybe do a fast selective search looking for killer tactical
>>>>>>>shots?
>>>>>>>
>>>>>>>Humans think differently on their time versus their opponent's time. Maybe
>>>>>>>computers would benefit from doing the same? I don't know enough about chess
>>>>>>>programming, however, to know how (or even _if_) the results of that "opponent's
>>>>>>>time search" could get passed to the "your time search". Would hash tables be
>>>>>>>sufficient?
>>>>>>
>>>>>>
>>>>>>This has been answered before...  here is the quick version of the idea:
>>>>>>
>>>>>>let's take two different pondering algorithms:  (1) present idea where we
>>>>>>assume that the best move from the last search is searched for the entire
>>>>>>time;  (2) alternative where the best N moves are searched (less deeply of
>>>>>>course).
>>>>>>
>>>>>>case 1:  target search time is 3 minutes.  The opponent takes three minutes
>>>>>>to make his move.
>>>>>
>>>>>This assumption is not correct.
>>>>>The opponent(espacially in cases that the opponent is human) may use 30 minutes
>>>>>for one move and less time for the other moves)
>>>>>
>>>>>I believe that in this case it is better to stop searching the best move after
>>>>>part of this time and start to consider the response for the second best move.
>>>>>
>>>>>Uri
>>>>
>>>>The same thinking applies.  I am _sure_ I am going to predict his move over
>>>>50% of the time. If he takes a long time, should I take a long time, or should
>>>>I do a bunch of three minute searches on different moves he might choose, and
>>>>after _his_ long think I play a move found after a 3 minute think?
>>>>
>>>>I think the current approach is best for _all_ circumstances...
>>>
>>>It is not clear.
>>>
>>>The benefit that you earn from another 3 minutes of search after you search for
>>>more time is smaller because of diminishing return from speed and in cases that
>>>you did not predict the move correctly in the first try you can earn the first 3
>>>minutes that are more important.
>>
>>Note that I don't necessarily agree with the concept of "diminishing returns"
>>when it comes to search depth.
>
>It is clear that there is also diminishing return in search depth.
>
>The average search depth that you get from another minute is lower when you use
>more time so if you decide to start analyzing a reply for another move after 9
>minutes of pondering you sacrifice less plies for the same target relative to
>the case that you do it after 3 minutes and it is logical to think that at some
>point the gain may be bigger than the sacrifice.
>
>Uri


I am not sure what you mean.  When I ran the crafty goes deep tests, the
search depth was pretty linear.  for every factor of 3x or so more time, it
went one more ply deeper.  I didn't see any "wall" that it ran into.  It does
help if you run it with a huge hash for huge searches.



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